Windows HTTP.sys: Information disclosure vulnerability
Summary
A flaw in the Windows HTTP.sys kernel-mode HTTP driver exposes sensitive system information to an unauthorized control sphere (CWE-497). An attacker with local access and a low-privilege account can disclose this information. Attack complexity is high and the impact is limited to confidentiality. The flaw is not directly reachable from the internet.
Affected
- Windows 10 Version 1607 (10.0.14393.0 before 10.0.14393.9688)
- Windows 10 Version 1809 (10.0.17763.0 before 10.0.17763.9487)
- Windows 10 Version 21H2 (10.0.19044.0 before 10.0.19044.7846)
- Windows 10 Version 22H2 (10.0.19045.0 before 10.0.19045.7846)
- Windows 11 Version 23H2 (10.0.22631.0 before 10.0.22631.7711)
- Windows 11 Version 24H2 (10.0.26100.0 before 10.0.26100.9974)
- Windows 11 Version 25H2 (10.0.26200.0 before 10.0.26200.9974)
- Windows 11 Version 26H1 (10.0.28000.0 before 10.0.28000.3501)
- Windows 11 Version 26H2 (10.0.26300.0 before 10.0.26300.9974)
- Windows Server 2016 including Server Core (10.0.14393.0 before 10.0.14393.9688)
- Windows Server 2019 including Server Core (10.0.17763.0 before 10.0.17763.9487)
- Windows Server 2022 (10.0.20348.0 before 10.0.20348.5870)
- Windows Server 2025: not listed in the CNA excerpt; check the MSRC page
Fixed in
- Install the Microsoft November 2026 security update for each affected version (the KB number per version must be confirmed on the MSRC page)
- Fixed builds according to the CNA record: 14393.9688, 17763.9487, 19044.7846, 19045.7846, 22631.7711, 26100.9974, 26200.9974, 28000.3501, 26300.9974, 20348.5870
- Build numbers for Server 2025 are unverified
Workaround
Unknown. No vendor-documented workaround was found. Apply the security update.
Exploitation
- Not known to be exploited in the wild (SANS ISC and Rapid7 sources)
- No public proof of concept found
- Microsoft CNA vector uses exploit maturity E:U (unproven)
- Not verified in CISA KEV
Our recommendation
- Install the November 2026 cumulative update on all affected systems, prioritising servers and multi-user systems, terminal servers and hosts where untrusted users have logons
- Check whether older systems (Windows 10 1607/1809, Server 2016/2019) still receive updates under Extended Security Updates
- Restrict local logons to trusted users where possible
- Check the MSRC page for the exact KB numbers and any interim mitigation
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Information disclosure – Windows HTTP.sys
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131291, KB5131085, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide (MSRC) msrc.microsoft.com
- CVE Record CVE-2026-119942 www.cve.org
- Strix CVE-2026-119942 www.strix.ai
- SANS ISC diary isc.sans.edu
- Rapid7 Patch Tuesday November 2026 www.rapid7.com
- Action1 Patch Tuesday November 2026 www.action1.com
- Senserva KB5132061 senserva.com
- Cybersecurity News Patch Tuesday November 2026 cybersecuritynews.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 20:17.
Original description (NVD)
Exposure of sensitive system information to an unauthorized control sphere in Windows HTTP.sys allows an authorized attacker to disclose information locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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